Dispersant for carbon black-filled foam

ABSTRACT

A closed cell, rigid, polymer foam comprising the reaction product of a polyisocyanate and an isocyanate-reactive compound in the presence of (a) a foaming agent, (b) at least about 2 percent by weight of carbon black, based on the weight of the polymer in the foam, and (c) a capped polyoxyalkylene compound which helps bring about a uniform dispersion of the carbon black throughout the foam so that the aged k-factor of the foam is below the aged k-factor of the corresponding unfilled foam.

This is a division of application Ser. No. 07/751,393, filed Aug. 28,1991.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the formation of dispersions of carbon blackfor use in the production of foam insulating products, particularlypolyurethane and polyisocyanurate foams.

2. Description of the Prior Art

The use of carbon black to reduce the aged k-factor and hence improvethe insulation value of closed cell, rigid, polymer foams is disclosedin U.S. Pat. No. 4,795,763. This patent establishes that uniformlydispersed carbon black filler effects a significant permanent reductionin the aged k-factor of foams. A failure to properly disperse the carbonblack and stabilize the dispersion can result in clogging of the foamproduction equipment and the production of foam wherein the carbon blackis clustered at the foam cell struts or highly agglomerated in a portionof the cell walls to yield little or no improvement in insulation value.It is accordingly highly desirable to find ways to simply andeconomically disperse carbon black in the ingredients employed in foamproduction and stabilize the dispersion, and thereafter form highlyinsulating foams from the dispersed mixture.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to produce closedcell, rigid foam plastic, especially polyurethane and polyisocyanuratefoam, which contains a well-dispersed carbon black filler and exhibitsoverall good properties, including excellent thermal insulativeproperties, good dimensional stability, thermal resistance andcompressive strength and acceptable friability.

It is another object of the present invention to provide an improvedmethod for the production of a carbon black-filled, rigid, highlyinsulating foam plastic, wherein the carbon black does not clog the foamproduction equipment and becomes uniformly dispersed in the cells of thefoam plastic product.

It is a further object of the present invention to provide an additivewhich helps to disperse carbon black in the ingredients employed in theproduction of filled, closed cell, rigid foam materials and stabilizethe dispersion, and to thereby bring about the production of superiorinsulating foams.

BRIEF DESCRIPTION OF DRAWING

The invention will now be described with reference to the accompanyingdrawing which is a side schematic elevation of an apparatus suitable forproducing a rigid foam laminate in accordance with the presentinvention.

DESCRIPTION OF THE INVENTION

The above objects have been achieved by the use of a polyoxyalkylenecompound in the production of carbon black-filled foam. Thepolyoxyalkylene additive helps to bring about a uniform dispersion ofthe carbon black in the foam-forming composition and maintain thedispersion without agglomeration of the carbon black during foaming,whereby the initial and long-term aged k-factors of the resultant foamare especially low, as compared to the unfilled foam of comparabledensity. The dispersion stabilizer suitably is rendered nonreactive withisocyanate groups by the capping of its oxyalkylene chain(s). Thepolyoxyalkylene compound can be represented broadly by the structuralformula

    capping group--polyoxyalkylene chain--Z,

wherein Z is an organic radical selected from aromatic, aliphatic,cycloaliphatic and heterocyclic radicals, and combinations of these, andt is an integer from 1 to 8. Any carbon black which can be uniformlydispersed in the foam at levels of about 1-20, preferably 2 to 10,weight %, based on the weight of the polymer in the foam, can be usedfor improvement of insulation value.

The carbon black and polyoxyalkylene dispersing agent can be added toone or more of the ingredients used to make the foam and mixedtherewith. For example, in the production of the preferred carbonblack-filled polyurethane and polyisocyanurate rigid foams of theinvention, the dispersing agent advantageously may be used to assist inthe dispersion of the carbon black in either the polyisocyanate or thepolyol or both. The dispersion(s) formed is then employed in the foampreparation. Superior insulating foams have been produced by dispersingthe carbon black in the isocyanate component, and utilizing as thedispersion stabilizer a polyoxyalkylene adduct having a reduced hydroxylnumber produced by reacting the terminal hydroxyl group(s) with acapping agent. The process of capping functional groups is well knownand common agents for masking the functionality of the hydroxyl groupare agents which produce esters and ethers. Polyalkylene oxide adducts,whose terminal hydroxyl groups suitably may be etherified or esterifiedso as to be rendered substantially non-reactive with the isocyanategroups during foam production, can be represented by the structuralformula

    R--(polyoxyalkylene chain)--R"

wherein R and R" independently represent a terminal group which isnonreactive with isocyanate groups, and may be selected from alkoxy,alkaryloxy, or acyloxy.

A particularly suitable oxyalkylene compound of the invention is aterminally esterified or etherified adduct of the general formula

    R--(CHR'--CH.sub.2 O).sub.n --CHR'--CH.sub.2 R"

wherein R and R", which are identical or different, denote a linear orbranched alkoxy radical with 1 to 22 C atoms, an alkaryloxy radical with10 to 18 C atoms, or an acyloxy radical with 1 to 18 C atoms, R' denoteshydrogen or a methyl radical, and n denotes a number between 0 and 20.

The preparation of the oxyalkylene additives is well known. One way ofpreparing them, for example, is to esterify polyethylene glycols withcarboxylic acids by the usual and known esterification methods. Linearas well as branched carboxylic acids with 1 to 18 C atoms can be used.Preferred, however, are lower carboxylic acids, such as acetic acid,which, in turn, is preferably used in the form of its anhydride for theesterification.

The etherification of the polyalkylene oxide adducts with lower alkylradicals is mainly effected by means of the known alkylation reagentssuch as methyl chloride, butyl chloride, or dimethyl or diethyl sulfate.

On the other hand, it is possible first to prepare esterified oretherified polyalkylene oxide adducts by adding alkylene oxide tocarboxylic acids, alcohols or alkyl phenols in known manner and thenesterifying or etherifying the free hydroxyl group by known methods. Thealcohols used according to this method can be linear or branched andcontain 1 to 22 C atoms, alcohols with 1 to 18 C atoms, and particularly1 to 13 C atoms, being generally preferred. As alkyl phenols, mainly thecommercially available octyl and nonyl phenols are used, butyl anddodecyl phenols being likewise used for this purpose. The carboxylicacids used according to this method are linear or branched and contain 1to 18 C atoms. A highly effective dispersant is a capped alkoxylated(especially ethoxylated) nonyl phenol, which preferably contains about 1to 4, more preferably about 1.5 to 2 moles of ethylene oxide per mole ofnonyl phenol. Acetic anhydride is a preferred capping agent.

The presence of a sufficiently large alkyl radical, such as onecontaining 8 to 14 C atoms (e.g., a nonyl or dodecyl group) may make itunnecessary to alkoxylate for effective dispersing performance. A cappedand non-alkoxylated phenol, such as nonylphenyl acetate, may thereforebe useful as a dispersing agent.

The dispersing agent is incorporated in the foam-forming mixture insufficient amount to bring about a fine dispersion of carbon blackparticles and stabilize the dispersion against re-agglomeration duringthe foaming process. The concentration of dispersing agent isadvantageously within the range of about 1 to 50 weight percent,preferably 2 to 35 weight percent, and more preferably 15 to 25 weightpercent, based on the total weight of the carbon black.

The amount of carbon black in the foam should be sufficient to obtainthe desired level of improved insulative properties. Typically, theamount ranges from about 3% to 10% by weight of the solid foam polymer,such as 4% to 9%, particularly 5.0% to 6.5%. The particle size of thecarbon black particles to be employed may vary, but generally the carbonblack has a mean particle diameter of from about 10 to 150, preferablyfrom 20 to 100, and more preferably from 30 to 75, nm.

The carbon black may be any of the different kinds available, such aslampblack, channel black, gas furnace black, oil furnace black andthermal black. Particularly suitable carbon blacks arenon-electroconductive and have an average particle diameter which ispreferably greater than about 20 and more preferably greater than about30, nm. This carbon black material has a specific surface area which ispreferably less than about 200, more preferably less than about 142 andmost preferably less than about 100, m² /g. Pelleted types of carbonblacks have been found especially suitable for large-scale processing.

A preferred carbon black is a standard rubber-grade carbon black fallingunder the classification of ASTM-550. This small-particle, highstructured black provides a highly stable carbon black/isocyanatedispersion. Its high structure serves to reduce grinding time whilestill producing a fine particle size distribution. The carbonblack/isocyanate dispersion containing the polyoxyalkylene dispersingaid is advantageously ground to a Hegman level of 8. There is aconcomitant considerable increase in dispersion viscosity due to thefine dispersion, but the high viscosity is handleable by the use ofconventional processing techniquds and equipment, such as large diameterpiping, high pressure pumps, static mixers, etc.

Two preferred ASTM-550 grade carbon blacks are pelleted products ofColumbian Chemicals Company, sold under the trademark, Raven 520, and ofCabot Corporation, sold under the trademark, Black Pearls 280, whichboth have a mean particle diameter of 41 nanometers.

Various methods for introducing and dispersing the carbon black andpolyoxyalkylene dispersant into the foam-forming system can be employed.Any machine already known in the art for dispersing carbon black inorganic media can be used, such as, for example, a Banbury mixer, a rollmill, a single- or twin-screw extruder, a media mill and the like. It isgenerally preferred to utilize the machine for the formation of apre-blend of the carbon black and the polyoxyalkylene compound in thefoam-forming ingredient(s) which constitutes the best medium forproviding the highest loading of finely divided and well-dispersedfiller particles and also a workable viscosity. This pre-blended mixtureis next thoroughly mixed with the remainder of the foam-formingmaterial, and the resultant total mixture is foamed and cured.Dispersion of the carbon black is conducted to provide the finest grindof particles economically attainable for easier processing and extendingthe life of the process equipment.

Preferred carbon black-filled organic foams of the invention comprisethe reaction products in the presence of a foaming agent ofpolyisocyanates and polyfunctional, active hydrogen-containing compounds(hereinafter called "isocyanate-reactive compounds"), especiallypolyhydroxyl compounds. In the manufacture of the preferred rigidcellular polyurethanes and polyisocyanurates, it is common practice toutilize two preformulated components, commonly called the A-componentand the B-component. Typically, the A-component contains the isocyanatecompound that must be reacted with the polyol of the B-component to formthe foam, and the balance of the foam-forming ingredients aredistributed in these two components or in yet another component orcomponents. The polyoxyalkylene additive is advantageously used to helpdisperse the carbon black particles in the polyisocyanate, and theresultant dispersion may then be combined with any other A-componentingredient(s) and the remaining foaming components. The reaction may becarried out in the presence of catalysts, auxiliaries and additives asrequired (e.g., a surfactant).

The polyisocyanate component employed in the preparation of the carbonblack-filled rigid foams of the invention can be any of thepolyisocyanates known to be useful in the art of polymer formation.Suitable organic polyisocyanates include aliphatic, cycloaliphatic,araliphatic, aromatic and heterocyclic polyisocyanates and combinationsthereof characterized in having two or more isocyanate (NCO) groups permolecule. Aromatic polyisocyanates are especially preferred. Theviscosity of the polyisocyanates suitably is in the range of 100 to 5000centipoise at 25° C.

Among the many isocyanates suitable for the practice of the subjectinvention are, for example, tetramethylene, hexamethylene, octamethyleneand decamethylene diisocyanates, and their alkyl substituted homologs,1,2-, 1,3- and 1,4-cyclohexane diisocyanates, 2,4- and2,6-methylcyclohexane diisocyanates, 4,4'- and2,4'-dicyclohexyl-diisocyanates, 4,4'- and 2,4'-dicyclohexylmethanediisocyanates, 1,3,5-cyclohexane triisocyanates, saturated(hydrogenated) polymethylene polyphenyl polyisocyanates,isocyanatomethylcyclohexane isocyanates, isocyanatoethyl-cyclohexaneisocyanates, bis(isocyanatomethyl)-cyclohexane diisocyanates, 4,4'- and2,4'-bis(isocyanatomethyl) dicyclohexane, isophorone diisocyanate, 1,2-,1,3-, and 1,4-phenylene diisocyanates, 2,4- and 2,6-toluenediisocyanates, 2,4'-, 4,4'- and 2,2-biphenyl diisocyanates, 2,2'-, 2,4'-and 4,4'-diphenylmethane diisocyanates, polymethylene polyphenylpolyisocyanates (polymeric MDI), and aromatic aliphatic isocyanates suchas 1,2-, 1,3-, and 1,4-xylylene diisocyanates.

Organic isocyanates containing heteroatoms may also be utilized, forexample those derived from melamine. Modified polyisocyanates, such ascarbodiimide or isocyanurate can also be employed. Liquid carbodiimidegroup- and/or isocyanurate ring-containing polyisocyanates havingisocyanate contents from 15 to 33.6 percent by weight, preferably from21 to 31 percent by weight, are also effective, for example, those basedon 4,4'-, 2,4'-, and/or 2,2'-diphenylmethane diisocyanate and/or 2,4-and/or 2,6-toluene diisocyanate, and preferably 2,4- and 2,6-toluenediisocyanate and the corresponding isomer mixtures, 4,4'-, 2,4', and2,2'-diphenylmethane diisocyanates as well as the corresponding isomermixtures, for example, mixtures of 4,4'- and 2,4'-diphenylmethanediisocyanates, mixtures of diphenylmethane diisocyanates and polyphenylpolymethylene polyisocyanates (polymeric MDI), and mixtures of toluenediisocyanates and polymeric MDI. Preferred, however, are the aromaticdiisocyanates and polyisocyanates. Particularly preferred are 2,4-, and2,6-toluene diisocyanate and mixtures thereof (TDI), 2,4'-, 2,2'- and4,4'-diphenylmethane diisocyanate (MDI), polymethylene polyphenylpolyisocyanates (polymeric MDI), and mixtures of the above preferredisocyanates.

Most particularly preferred are the polymeric MDI's. Preferredpolymethylene polyphenylisocyanates desirably have a functionality of atleast 2.1 and preferably 2.5 to 3.2 These preferred polymethylenepolyphenylisocyanates generally have an equivalent weight between 120and 180 and preferably have an equivalent weight between 130 and 145.Especially high quality carbon black-filled foams have been producedfrom polymeric MDI's having a viscosity above 1000, and preferablybetween about 1700-2500, centipoise at 25° C.

Highly useful organic polyisocyanates are the isocyanate terminatedquasi-prepolymers. These quasiprepolymers are prepared by reactingexcess organic polyisocyanate or mixtures thereof with a minor amount ofan active hydrogen-containing compound. Suitable active hydrogencontaining compounds for preparing the quasiprepolymers hereof are thosecontaining at least two active hydrogen-containing groups which areisocyanate reactive. Typifying such compounds are hydroxyl-containingpolyesters, polyalkyleneetherpolyols,hydroxyl-terminatedpolyurethaneoligomers, polyhydric polythioethers, ethylene oxide adducts ofphosphorous-containing acids, polyacetals, aliphatic polyols, aliphaticthiols including alkane, alkene and alkyne thiols having two or more SHgroups; as well as mixtures thereof. Compounds which contain two or moredifferent groups within the above-defined classes may also be used suchas, for example, compounds which contain both an SH group and an OHgroup. Highly useful quasiprepolymers are disclosed in U.S. Pat. No.4,791,148 and U.S. application Ser. No. 07/342,508, filed Apr. 24, 1989,the disclosures of which with respect to the quasiprepolymers are herebyincorporated by reference.

In addition to the polyisocyanate, the foam-forming formulation alsocontains an organic compound containing at least 1.8 or moreisocyanate-reactive groups per molecule an isocyanate-reactivecompound). Suitable such compounds include polyols, polyamines,polyacids, polymercaptans and like compounds. Preferredisocyanate-reactive compounds are the polyester and polyether polyols.Particularly preferred are polyester polyols or mixtures of polyesterand polyether polyols.

The polyester polyols can be prepared by known procedures from apolycarboxylic acid component comprising a polycarboxylic acid or acidderivative, such as an anhydride or ester of the polycarboxylic acid,and any polyol component. The polyol component advantageously comprisesa glycol(s) or a glycol-containing mixture of polyols. The polyacidand/or polyol components may, of course, be used as mixtures of two ormore compounds in the preparation of the polyester polyols. Particularlysuitable polyester polyols for use in the foam production are aromaticpolyester polyols containing phthalic acid residues.

The production of the polyester polyols is accomplished by simplyreacting the polycarboxylic acid or acid derivative with the polyolcomponent in a known manner until the hydroxyl and acid values of thereaction mixture fall in the desired range. The reaction typically isperformed at temperatures from about 150° C. to 250° C. for a periodfrom about 1 to 10 hours. The reaction can be carried out as a batchprocess or continuously. When present, excess glycol can be distilledfrom the reaction mixture during and/or after the reaction, such as inthe preparation of low free glycol-containing polyester polyols usablein the present invention. Normally, an effective amount of catalyst isadded to promote the present reaction. Any conventional esterificationor transesterification catalyst (single compound or mixture ofcompounds) can be used. Suitable catalysts include organotin compounds,particularly tin compounds of carboxylic acids, such as stannousoctoate, stannous oleate, stannous acetate, stannous laurate, dibutyltin dilaurate, and other such tin salts. Additional suitable metalcatalysts include tetraisopropyl titanate, and other such titanatesalts, and the like.

After transesterification or esterification, the reaction product can bereacted with an alkylene oxide to form a polyester polyol mixture of theinvention. This reaction desirably is catalyzed. The temperature of thisprocess should be from about 80° C. to 170° C., and the pressure shouldgenerally range from about 1 to 40 atmospheres.

The polycarboxylic acid component may be aliphatic, cycloaliphatic,aromatic and/or heterocyclic and may optionally be substituted, forexample, by halogen atoms, and/or may be unsaturated. Examples ofsuitable carboxylic acids and derivatives thereof for the preparation ofthe polyester polyols include: oxalic acid; malonic acid; succinic acid;glutaric acid; adipic acid; pimelic acid; suberic acid; azelaic acid;sebacic acid; phthalic acid; isophthalic acid; trimellitic acid;terephthalic acid; phthalic acid anhydride; tetrahydrophthalic acidanhydride; pyromellitic dianhydride; hexahydrophthalic acid anhydride;tetrachlorophthalic acid anhydride; endomethylene tetrahydrophthalicacid anhydride; glutaric acid anhydride; maleic acid; maleic acidanhydride; fumaric acid; dibasic and tribasic unsaturated fatty acidsoptionally mixed with monobasic unsaturated fatty acids, such as oleicacid; terephthalic acid dimethyl ester and terephthalic acid-bis glycolester.

Polyester polyols whose acid component advantageously comprises at leastabout 30% by weight of phthalic acid residues are particuarly useful. Byphthalic acid residue is meant the group ##STR1## While the aromaticpolyester polyols can e prepared from substantially pure reactantmaterials, more complex ingredients are advantageously used, such as theside-stream, waste or scrap residues from the manufacture of phthalicacid, terephthalic acid, dimethyl terephthalate, polyethyleneterephthalate, and the like. Particularly suitable compositioncontaining phthalic acid residues for use int he invention are (a)ester-containing by-products from the manufacture of dimethylterephthalate, (b) scrap polyalkylene terephthalates, (c) phthalicanhydride, (d) residues from the manufacture of phthalic acid orphthalic anhydride, (e) terephthalic acid, (f) residues from themanufacture of terephthalic acid, (g) isophthalic acid and (h)trimellitic anhydride, and (i) combinations thereof. These compositionmay be converted by reaction with the polyols of the invention topolyester polyols through conventional transesterification oresterification procedures.

A preferred polycarboxylic acid component for use in the preparation ofthe aromatic polyester polyols is phthalic anhydride. This component canbe replaced by phthalic acid or a phthalic anhydride bottomscompositions, a phthalic anhydride crude compositions, or a phthalicanhydride light ends composition, as such compositions are defined inU.S. Pat. No. 4,529,744.

Other preferred materials containing phthalic acid residues arepolyalkylene terephthalates, especially polyethylene terephthalate(PET), residues or scraps.

Still other preferred residues are DMT process residues, which are wasteor scrap residues from the manufacture of dimethyl terephthalate (DMT).The term "DMT process residue" refers to the purged residue which isobtained during the manufacture of DMT in which p-xylene is convertedthrough oxidation and esterification with methanol to the desiredproduct in a reaction mixture along with a complex mixture ofby-products. The desired DMT and the volatile methyl p-toluateby-product are removed from the reaction mixture by distillation leavinga residue. The DMT and methyl p-toluate are separated, the DMT isrecovered and methyl p-toluate is recycled for oxidation. The residuewhich remains can be directly purged from the process or a portion ofthe residue can be recycled for oxidation and the remainder divertedfrom the process, or, if desired, the residue can be processed further,as, for example, by distillation, heat treatment and/or methanolysis torecover useful constituents which might otherwise be lost, prior tourging the residue from the system. The residue which is finally purgedfrom the process, either with or without additional processing, isherein called DMT process residue.

These DMT process residues may contain DMT, substituted benzenes,polycarbomethoxy diphenyls, benzyl esters of the toluate family,dicarbomethoxy fluorenone, carbomethoxy benzocoumarins and carbomethoxypolyphenols. Cape Industries, Inc. sells DMT process residues under thetrademark Terate® 101. DMT process residues having a differentcomposition but still containing the aromatic esters and acids are alsosold by DuPont and others. The DMT process residues to betransesterified in accordance with the present invention preferably havea functionality at least slightly greater than 2.

Such suitable residues include those disclosed in U.S. Pat. Nos.3,647,759, 4,411,949, 4,714,717, and 4,897,429, the disclosures of whichwith respect to the residues are hereby incorporated by reference.

The polyester polyols are prepared from the above describedpolycarboxylic acid components and any polyol component. The polyols canbe aliphatic, cycloaliphatic, aromatic and/or heterocyclic. Lowmolecular weight aliphatic polyhydric alcohols, such as aliphaticdihydric alcohols having no more than about 20 carbon atoms are highlysatisfactory. The polyols optionally may include substituents which areinert in the reaction, for example, chlorine and bromine substituents,and/or may be unsaturated. Suitable amino alcohols, such as, forexample, monoethanolamine, diethanolamine, triethanolamine, or the likemay also be used. Moreover, the polycarboxylic acid(s) may be condensedwith a mixture of polyhydric alcohols and amino alcohols.

A preferred polyol component is a glycol. The glycols may containheteroatoms (e.g., thiodiglycol) or may be composed solely of carbon,hydrogen, and oxygen. They are advantageously simple glycols of thegeneral formula C_(n) H_(2n) (OH)₂ or polyglycols distinguished byintervening ether linkages in the hydrocarbon chain, as represented bythe general formula C_(n) H_(2n) O_(x) (OH)₂. In a preferred embodimentof the invention, the glycol is a low molecular weight aliphatic diol ofthe generic formula:

    HO--R--OH

wherein R is a divalent radical selected from the group consisting of:

(a) alkylene radicals each containing from 2 through 6 carbon atoms, and

(b) radicals of the formula:

    --(R.sup.1 O).sub.m --R.sup.1 --

wherein R' is an alkylene radical containing from 2 through 6 carbonatoms, and m is an integer of from 1 through 4, and

(c) mixtures thereof.

Examples of suitable polyhydric alcohols include: ethylene glycol;propylene glycol-(1,2) and -(1,3); butylene glycol-(1,4) and -(2,3);hexane diol-(1,6); octane diol-(1,8); neopentyl glycol;1,4-bishydroxymethyl cyclohexane; 2-methyl-1,3-propane diol; glycerin;trimethylolpropane; trimethylolethane; hexane triol-(1,2,6); butanetriol-(1,2,4); pentaerythritol;quinol; mannitol; sorbitol; methylglucoside; diethylene glycol; triethylene glycol; tetraethylene glycoland higher polyethylene glycols; dipropylene glycol and higherpolypropylene glycols as well as dibutylene glycol and higherpolybutylene glycols. Especially suitable polyols are alkylene glycolsand oxyalkylene glycols, such as ethylene glycol, diethylene glycol,dipropyleneglycol, triethylene glycol, tripropylene glycol,tetraethylene glycol, tetrapropylene glycol, trimethylene glycol andtetramethylene glycol, and 1,4-cyclohexanedimethanol(1,4-bis-hydroxymethyl-cyclohexane).

The term "polyester polyol" as used in this specification and claimsincludes any minor amounts of unreacted polyol remaining after thepreparation of the polyester polyol and/or unesterified polyol (e.g.,glycol) added after the preparation. The polyester polyol canadvantageously include up to about 40 weight percent free glycol.

The polyester polyols advantageously have an average functionality ofabout 1.8 to 8, preferably about 1.8 to 5, and more preferably about 2to 2.5. Their hydroxyl number values generally fall within a range ofabout 15 to 750, preferably about 30 to 550, and more preferably about100 to 550, and their free glycol content generally is from about 0 to40, preferably from 2 to 30, and more preferably from 2 to 15, weightpercent of the total polyester polyol component.

Examples of suitable polyester polyols are those derived from PET scrapand available under the designation Chardol 170, 336A, 560, 570, 571 and572 from Chardonol and Freol 30-2150 from Freeman Chemical. Examples ofsuitable DMT derived polyester polyols are Terate® 202, 203, 204, 254and 254A polyols, which are available from Cape Industries. Phthalicanhydride derived-polyester polyols are commercially available under thedesignation Pluracol® polyol 9118 from BASF Corporation, and StepanolPS-2002, PS-2402, PS-2502A, PS-2502, PS-2522, PS-2852, PS-2852E,PS-2552, and PS-3152 from Stepan Company.

The polyols which can be employed alone or in combination with polyesterpolyols in the preparation of the carbon black-filled polyurethane andpolyisocyanurate foam compositions of the invention include monomericpolyols and polyether polyols. The polyether polyols are foundparticularly useful in preparing rigid polyurethane foams. Polyetherpolyols of this type are the reaction products of a polyfunctionalactive hydrogen initiator and a monomeric unit such as ethylene oxide,propylene oxide, butylene oxide and mixtures thereof, preferablypropylene oxide, ethylene oxide or mixed propylene oxide and ethyleneoxide. The polyfunctional active hydrogen initiator preferably has afunctionality of 2-8, and more preferably has a functionality of 3 orgreater (e.g., 4-8).

A wide variety of initiators may be alkoxylated to form useful polyetherpolyols. Thus, for example, polyfunctional amines and alcohols of thefollowing type may be alkoxylated: monoethanolamine, diethanolamine,triethanolamine, ethylene glycol, polyethylene glycol, propylene glycol,hexanetriol, polypropylene glycol, glycerine, sorbitol,trimethylolpropane, pentaerythriotol, sucrose and other carbohydrates.Such amines or alcohols may be reacted with the alkylene oxide(s) usingtechniques known to those skilled in the art. The hydroxyl number whichis desired for the finished polyol would determine the amount ofalkylene oxide used to react with the initiator. The polyether polyolmay be prepared by reacting the initiator with a single alkylene oxide,or with two or more alkylene oxides added sequentially to give a blockpolymer chain or at once to achieve a random distribution of suchalkylene oxides. Polyol blends such as a mixture of high molecularweight polyether polyols with lower molecular weight polyether polyolscan also be employed.

The polyurethane foams can be prepared by reacting the polyol andpolyisocyanate on a 0.7:1 to 1.1:1 equivalent basis. In an advantageousembodiment of the invention wherein the polyester polyols are combinedwith another polyol(s) to produce polyurethane foams, the polyesterpolyols can comprise about 5 to 100, preferably about 5 to 75, and morepreferably about 20 to 50, weight percent of the total polyol content inthe foam preparations. The polyisocyanurate foams of the invention areadvantageously prepared by reacting the polyisocyanate with a minoramount of polyol, such as sufficient polyol to provide about 0.10 to0.70 hydroxyl equivalents of polyol per equivalent of saidpolyisocyanate, wherein the polyester polyol comprises about 5 to 100,and preferably about 50 to 100, weight percent of the total polyolcontent in the foam preparations.

Any suitable blowing agent can be employed in the foam compositions ofthe present invention. Water, air, nitrogen, carbon dioxide, readilyvolatile organic substances and/or compounds which decompose to liberategases (e.g., axo compounds may be used). Typically, these blowing agentsare liquids having a boiling point between minus 50° C. and plus 100° C.and preferably between 0° C. and 50° C. The preferred liquids arehydrocarbons or halohydrocarbons. Examples of suitable blowing agentsinclude, among other, chlorinated and fluorinated hydrocarbons such astrichlorofluoromethane, CCl₂ FCClF₂, CCl₂ FCG₂ H, CClFHCClF₂,trifluorochloropropane, difluorodichloromethane,1-fluoro-1,1-dichloroethane,2,2,2-rifluoro-1,1-dichloroethane,,1,1-difluoro-1-chloroethane,chlorodifluoromethane, emthylene chloride, diethylether, isopropylether, n-pentane, cyclopentane, 2-methylbutane, methyl formate, carbondioxide and mixtures thereof. Trichlorofluoromethane is a preferredblowing agent.

In a preferred embodiment of the invention, the foams are produced usinga froth-foaming method, such as the one disclosed in U.S. Pat. No.4,572,865, whose disclosure is hereby incorporated by reference. In thismethod, the frothing agent can be any material which is inert to thereactive ingredients and easily vaporized at atmospheric pressure. Thefrothing agent advantageously has an atmospheric boiling point of -50°C. to 10° C., and includes carbon dioxide, dichlorodifluoromethane,monochlorodifluoromethane, trifluoromethane, monochlorotrifluoromethane,monochloropentafluoroethane, vinylfluoride, vinylidenefluoride,1,1-difluoroethane, 1,1,1-trichlorodifluoroethane, and the like.Particularly preferred are dichlorodifluoromethane andmonochlorodifluoromethane. A higher boiling blowing agent is desireablyused in conjunction with the frothing agent. The blowing agent is agaseous material at the reaction temperature and advantageously has anatmospheric boiling point ranging from about 10° to 80° C. Suitableblowing agents include trichlorofluoromethane,1,1,2-trichloro-1,2,2-trifluoroethane, acetone, pentane, and the like,preferably trichlorofluoromethane.

The foaming agents, e.g., trichlorofluoromethane blowing agent orcombined trichlorofluoromethane blowing agent anddichlorodifluoromethane frothing agent, are employed in an amountsufficient to give the resultant foam the desired bulk density which isgenerally between 0.5 and 10, preferably between 1 and 5, and mostpreferably between 1.5 and 2.5, pounds per cubic foot. The foamingagents generally comprise from 1 to 30, and preferably comprise from 5to 20 weight percent of the composition. When a foaming agent has aboiling point at or below ambient, it is maintained under pressure untilmixed with the other components. Alternatively, it can be maintained atsubambient temperatures until mixed with the other components. Mixturesof foaming agents can be employed. Hydrogen-containing halocarbons knownas HCFS's, which are considered environmentally acceptable in that theytheoretically have minimal effect on ozone depletion, may be substitutedfor the fully halogenated chlorofluorocarbons such as CFCl₃ (CFC-11) andCF₂ CL₂ (CFC-12).

Any suitable surfactant can be employed in the foams of this invention.Successful results have been obtained with silicone/ethyleneoxide/propylene oxide copolymers as surfactants. Examples of surfactantsuseful in the present invention include, among others,polydimethylsiloxane-polyoxyalkylene block copolymers available from theUnion Carbide Corporation under the trade names "Y-10222", "L-5420" and"L-5340", from the Dow Corning Corporation under the trade names"DC-193" and "DC-5315", and from Goldschmidt Chemical Corporation underthe tradenames "B-8408" and "B-8407". Other suitable surfactants arethose described in U.S. Pat. Nos. 4,365,024 and 4,529,745 and suppliedby Sloss Industries Corporation under the trademarks Foamstab 100 and200. Generally, the surfactant comprises from about 0.05 to 10, andpreferably from 0.1 to 6, weight percent of the foam-formingcomposition.

Any of the catalysts conventionally employed in the art to catalyze thereaction of an isocyanate with an isocyanate-reactive compound can beemployed in the foam preparations of the invention. Such catalystsinclude organic and inorganic acid salts of, and organometallicderivatives of, bismuth, lead, tin, iron, antimony, uranium, cadmium,cobalt, thorium, aluminum, mercury, zinc, nickel, cerium, molybdenum,vanadium, copper, manganese, and zirconium, as well as phosphines andtertiary organic amines. Examples of such catalysts are dibutyltindilaurate, dibutyltin diacetate, stannous octoate, lead octoate, cobaltnaphthenate, tricthylamine, triethylenediamine,N,N,N',N'-tetramethylethylenediamine, 1,1,3,3-tetramethylguanidine, N,N, N'N'-tetramethyl-1,3-butanediamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, and the like. The catalysts generally comprisefrom about 0.1 to 20, and preferably from 0.3 to 10, weight percent ofthe total foam-forming composition.

In the preparation of the polyisocyanurate rigid foams, any catalystsknown to catalyze the trimerization of isocyanates to formisocyanurates, and to catalyze the reaction of isocyanate groups withhydroxyl groups to form polyurethanes, can be employed. One preferredtype of catalyst is a mixture of a tertiary amino phenol, such as2,4,6-tris(dimethylaminomethyl)phenol (sold by Rohm and Haas Co. underthe designation "DMP-30"), and an alkali metal carboxylate, such aspotassium-2-ethyl hexoate, the synthesis and use of which are describedin U.S. Pat. No. 4,169,921. The disclosure of this patent is herebyincorporated by reference. The equivalent ratio of tertiary amino phenolto alkali metal carboxylate in the cocatalyst composition is desirablyabout 0.4:1 to 2.5:1. Another preferred catalyst system is a mixturecomprising (i) a salt of a low molecular weight carboxylic acid selectedfrom the group consisting of an alkali metal salt and an alkaline earthmetal salt and mixtures thereof (e.g., potassium acetate), (ii) a saltof a higher molecular weight carboxylic acid selected from the groupconsisting of an alkali metal salt and an alkaline earth metal salt andmixtures thereof, the higher molecular weight carboxylic acid havingfrom about 5 to 30 carbon atoms (e.g. potassium octoate), and (iii) atertiary amine (e.g., 2,4,6-tris [dimethylaminomethyl]phenol). Thismixture is described in U.S. Pat. No. 4,710,521, whose disclosure ishereby incorporated by reference.

Other additives may also be included in the foam formulations. Includedare processing aids, viscosity reducers, such as1-methyl-2-pyrrolidinone, propylene carbonate, nonreactive and reactiveflame retardants, such as tris(2-chloroethyl)-phosphate, otherdispersing agents, reinforcing agents, plasticizers, mold releaseagents, stabilizers against aging and weathering, compatibility agents,fungistatic and bacteriostatic substances, dyes, other fillers andpigments, and other additives. The use of such additives is well knownto those skilled in the art.

The polyisocyanurate and polyurethane foams can be prepared by mixingtogether the organic polyisocyanate with the isocyanate-reactivecompound (e.g., polyol) and other foam-forming ingredients, includingthe carbon black and dispersing agent, at temperatures ranging fromabout 0° C. to 150° C. Any order of mixing is acceptable provided thatthe carbon black is homogeneously blended into the foam-formingformulation and the reaction of the polyisocyanate andisocyanate-reactive compound does not begin until all components aremixed. In a preferred embodiment, the dispersing agent is employed toform a uniform dispersion of the carbon black in the isocyanate, thisdispersion is thoroughly mixed with the blowing or foaming agent andsurfactant to form the A-component, and then the A-component is combinedwith the remaining components, whereupon the total mixture is foamed.

The foams may be produced by discontinuous or continuous processes, withthe foaming reaction and subsequent curing being carried out in molds oron conveyors. The foam product may be suitably produced as a foamlaminate by (a) contacting at least one facing sheet with theform-forming mixture, and (b) foaming the mixture. The process isadvantageously conducted in a continuous manner by depositing thefoam-forming mixture on a facing sheet(s) being conveyed along aproduction line, and preferably placing another facing sheet(s) on thedeposited mixture. The deposited foam-forming mixture is convenientlythermally cured at a temperature from about 20° C. to 150° C. in asuitable apparatus, such as an oven or heated mold. Both free rise andrestrained rise processes, such as disclosed in U.S. Pat. No. 4,572,865,may be employed in the foam production.

One preferred method of utilizing the carbon black/polyisocyanatedispersion in the foam-forming process of the invention can beillustrated with reference to the apparatus shown in the drawing. Theapparatus includes tanks 10, 11 and 12 for containing the foamableingredients and additives such as surfactant, dye, blowing agent, etc.The tanks are charged with the foam-forming mixture in whatever manneris convenient and preferred for the given mixture. For instance, in theproduction of an isocyanurate foam, the foam-forming mixture can bedivided into three liquid components, with the carbonblack/polyisocyanate mixture, surfactant, and blowing agent in tank 10,the polyol in tank 11, and the catalyst in tank 12, each respectivelyconnected to outlet lines 13, 14 and 15. The temperatures of theingredients are controlled to ensure satisfactory processing. The lines13, 14 and 15 form the inlet to metering pumps 16, 17 and 18. Theapparatus is also provided with a storage tank (not shown) for afrothing agent. This tank discharges into conduit 19 which opens at"T"-intersection 20 into line 13. A check valve 21 and ball valve 22 inconduit 19 ensure no backup of material toward the frothing agentstorage tank. The frothing agent instead can be introduced in the sameway into line 14 or both lines 13 and 14. The pumps 16, 17 and 18discharge respectively through lines 23, 24 and 25. Lines 24 and 25comprise branches which open into line 26, and lines 23 and 26 are inturn respectively connected to flexible lines 27 and 28. The flexiblelines 27 and 28 discharge to mixing head 29. The apparatus is alsoprovided with a roll 30 of lower facing material 31, and a roll 30' ofupper facing material 31'. Where only a lower facing material is used,the upper facing material can be replaced with a web coated with arelease agent. The apparatus is also provided with metering rolls 32 and33, and an oven 34 provided with vents 35 and 35' for introducing andcirculating hot air. The apparatus also includes pull rolls 36 and 37,each of which preferably has a flexible outer sheath 38 and 39, andcutting means 40a for cutting off side excess material and 40 b forsevering the faced foam plastic produced into finite lengths, therebyproducing discrete panels.

As an example of the operation, tank 10 is charged with the organicpolyisocyanate/carbon black dispersion, blowing agent and surfactant,tank 11 is charged with the polyol, and tank 12 is charged with thecatalyst composition. The speeds of the pumps 16, 17 and 18 are adjustedto give the desired ratios of the ingredients contained in the tanks 10,11 and 12, whereupon these ingredients pass respectively into lines 13,14 and 15. When a froth-foaming process is conducted, the frothing agentis injected into line 13 upstream of metering pump 16. The ingredientspass through lines 23, 24 and 25, as well as lines 26, 27 and 28,whereupon they are mixed in the mixing head 29 and deposited therefrom.By virtue of rotation of the pull rolls 36 and 37, the lower facingmaterial is pulled from the roll 30, whereas the upper facing materialis pulled from the roll 30'. The facing material passes over idlerrollers such as idler rollers 41 and 42 and is directed to the nipbetween the rotating metering rolls 32 and 33. The mixing head 29 iscaused to move back and forth, i.e., out of the plane of the drawing byvirtue of its mounting on a reciprocating means 43. In this manner, aneven amount of material can be maintained upstream of the nip betweenthe metering rolls 32, 33. The composite structure at this pointcomprising lower and upper facing material 31 and 31' havingtherebetween a foamable mixture 44 now passes into the oven 34 and onalong the generally horizontally extending conveyor. While in the oven34, the core expands under the influence of heat added by the hot airfrom vents 35 and 35' and due to the heat generated in the exothermicreaction between the polyol and isocyanate in the presence of thecatalyst. The temperature within the oven is controlled by varying thetemperature of the hot air from vents 35, 35' in order to ensure thatthe temperature within the oven 34 is maintained within the desiredlimits of 100° F. to 300° F., and preferably 175° F. to 250° F. Thefoam, under the influence of the heat added to the oven, cures to formfaced foam plastic 45. The product 45 then leaves the oven 34, passesbetween the pull rolls 36 and 37, and is cut by side edge and lengthcutting means 40a and 40b into finite lengths, thereby forming discretepanels 46 and 46' of the product.

Numerousmodifications to the above-described apparatus will beimmediately apparent to those skilled in the art. For example, the tanks10, 11 and 12 can be provided with refrigeration means in order tomaintain the reactants at subambient temperatures. In one modification,the frothing agent is not delivered into lines 13 or 14, but is admixedwith the foam-forming ingredient(s) in tanks 10 and/or 11. This approachis especially advantageous for handling large amounts of highly volatilefrothing agents, which can, for example, be apportioned in tanks 10 and11 which are specially adapted (e.g., pressurized) to hold the frothingagent-containing formulations.

As shown in the drawing, a reinforcing web 47 can be fed into theapparatus. Fiberglass fibers constitute a preferred web material. Forexample, in a preferred embodiment the reinforcing web will be the typeof glass mat used in producing the structural laminate of U.S. Pat. No.4,028,158, i.e., a thin mat of long, generally straight glass fibers. Bygenerally following the method of foam reinforcement described inExample 1 of U.S. Pat. No. 4,028,158 and utilizing a foam-formingmixture having the consistency of the liquid foamable mixture of thisexample, the glass mat becomes distributed within the foam core. Inaccordance with this embodiment, a thin mat 47 of glass fibers is fedfrom roll 48 toward the nip between the two rotating metering rolls 32and 33. By virtue of rotation of the pull rolls 36 and 37, reinforcingmat 47 is pulled from its roll, through the nip of the metering rollsand downstream to form an expanded reinforcement material in theresulting structural laminate.

When the foam-forming mixture deposited on the underlying substrateduring the process is in the form of a froth, an included reinforcingweb, such as the thin glass mat of U.S. Pat. No. 4,028,158, will bepushed under the influence of the expanding froth to a position adjacentand interior to its associated facing sheet. In this way, a reinforcingweb(s) can be placed interior to the lower or upper facing sheet or toboth, as described in U.S. Pat. No. 4,572,865, the disclosure of whichpatent with respect to such reinforced structural laminates is herebyincorporated by reference.

Any facing sheet previously employed to produce building panels can beemployed in the present invention. Examples of suitable facing sheetsinclude, among others, those of kraft paper, aluminum, asphaltimpregnated felts, and glass fiber mats as well as combinations of twoor more of the above.

The foam materials of the invention can also be used, with or without afacer(s), for pipe insulation, pour-in-place applications, bunstock,spray foam and the like.

The invention is further illustrated by the following example in whichall parts and percentages are by weight unless otherwise indicated.

EXAMPLE

This example illustrates (a) the preparation of a uniform dispersion ofcarbon black in a polyisocyanate and (b) the use of that dispersion inthe formation of a number of rigid polyisocyanurate foam products byreference to the drawing.

A. DISPERSION OF CARBON BLACK IN ISOCYANATE

The mill used to disperse the carbon black in the isocyanate was a 250gallon, high speed impingement mill (Kinetic Dispersions' Kady Mill).The mill was charged with 2000 lbs of Mondur MR-200 isocyanate andturned on. 38.6 lbs of the Dispersant (see Table below) were added andthe ingredients were allowed to mix for 5 minutes. 186 lbs of BlackPearls 280 carbon black were then added slowly. Mixing was continued forabout 45 minutes until a Hegman 8 level of dispersion was obtained.

B. A-COMPONENT PREPARATION

The above carbon black/isocyanate dispersion was used to prepareA-components according to the formulations shown in the Table below forInventive foams A, C and E. Comparative foams B, D and F were preparedin the absence of any carbon black and dispersant. The carbon blackdispersion (or neat isocyanate) was charged to a 1000 gallon mix tank10. Surfactant was then added during agitation. CFC-11 was added and theblend was allowed to mix for approximately 30 minutes.

C. LAMINATE PREPARATION

Structural laminates were prepared from the ingredients and quantitiesthereof shown in the Table. A free-rise process was employed. For eachstructural laminate, the B-component polyol was charged to tank 11, andthe C-component catalyst was charged to tank 12. Laminates A and Butilized aluminum foil/kraft paper/aluminum foil facings. Laminates Cand D utilized fibrous glass mat facings and froth foam. Laminates E andF utilized plain aluminum foil facings and core foam fibrous glassreinforcement.

In each case, Components A, B and C were brought together in a highpressure impingement foam head 29 in the proportions shown in the Table.In the case of Laminates C and D, the HCFC-22 (CHClF₂) was injected intothe isocyanate-containing component at the opening formed into conduit13. Top and bottom facings were fed together toward the nip of meteringrolls 32 and 33. The foam forming mixture was deposited onto the lowerfacing 31 and metered between the nip rolls to establish the finalproduct thickness. In the case of Laminates E and F, a thin mat 47 offibrous glass was fed into the core foam with the lower facing. Thelaminates proceeded through oven 34 to yield each of foam boards Athrough F.

The properties shown in the Table reveal that the inventive carbonblack-filled laminates (A, C and E) have improved insulation value overthe unfilled laminates (B, D and F) and are very comparable with respectto the other foam properties.

                                      TABLE                                       __________________________________________________________________________    PRODUCTION OF STRUCTURAL LAMINATES                                            INGREDIENTS: 10% TRIMER FOAMS                                                                          16% TRIMER FOAMS                                                                          18% TRIMER FOAMS                         (pts by wt)  A     B     C     D     E     F                                  __________________________________________________________________________    A-Component:                                                                  Isocyanate.sup.1                                                                           170.0 170.0 208.0 208.0 221.0 221.0                              Carbon black.sup.2                                                                         15.8  --    19.3  --    20.5  --                                 Dispersant.sup.3                                                                           3.3   --    4.0   --    4.3   --                                 Surfactant.sup.4                                                                           2.0   2.0   3.5   3.5   2.0   2.0                                CFC-11       53.0  53.0  39.0  41.0  55.0  58.0                               HCFC-22      --    --    6.0   6.0   --    --                                 B-Component: 130.0 130.0 92.0  92.0  79.0  79.0                               Polyester polyol.sup.5                                                        C-Component: 6.0   6.0   6.0   6.0   6.0   6.0                                Catalyst.sup.6                                                                FORM PROPERTIES:                                                              Density, pcf 1.75  1.70  1.77  1.69  1.80  1.67                               Closed cells, %                                                                            89.7  88.7  84.3  89.6  85.7  87.1                               Oxygen Index 22.25 21.75 23.25 23.50 25.75 25.00                              ASTM E-84                                                                     Flame spread 25    25    25    25    23    25                                 Smoke        76    108   72    68    35    51                                 Compressive strength, psi                                                                  21    27    29    31    22    25                                 k-factor (ASTM C-518)                                                         30 days      0.116 0.121 0.147 0.161 --    --                                 60 days      --    --    0.154 0.167 0.117 0.138                              __________________________________________________________________________     FOOTNOTES:                                                                    .sup.1 Isocyanate = polymethylene polyphenyl isocyanate which has an          equivalent weight of 138, an acidity of 0.02% HCl, and a viscosity of         2,000 centipoises at 25° C., and is available from the Mobay           Chemical Company under the trademark MONDUR MR200.                            .sup.2 Carbon black = Black Pearls 280 supplied by Cabot Corporation.         .sup.3 Dispersant = acetate capped ethoxylated nonyl phenol which contain     2 moles of ethylene oxide per mole of nonyl phenol and is supplied by         Pelron Corporation.                                                           .sup.4 Surfactant = silicone surfactant supplied by the Union Carbide         Corporation under the trademark Y10222.                                       .sup.5 Polyester polyol = reaction product of phthalic anhydride and          diethylene glycol (DEG) which has a hydroxyl number of 224-244 and a          viscosity at 25° C. of 2,500-3,000 cps, and is available from the      Stepan Company under the trademark Stepanpol PS2502A.                         .sup.6 Catalyst = mixture employed in the form of a solution in DEG in a      weight ratio of 1.18 potassium acetate:2.31 potassium octoate:0.69            DMP30:5.82 DEG.                                                          

I claim:
 1. A closed cell, rigid, polymer foam which comprises thereaction product of a polyisocyanate and an isocyanate-reactive compoundin the presence of (a) a foaming agent, (b) at least about 2 percent byweight of carbon black, based on the weight of the polymer in the foam,and (c) an end-capped polyoxyalkylene compound which is nonreactive withisocyanate groups, and is present in an amount sufficient to help bringabout a uniform dispersion of the carbon black throughout the foam sothat there is present in the cell walls of the foam an amount ofpredominantly non-agglomerated carbon black which reduces the agedk-factor of the foam to below the aged k-factor of the correspondingunfilled foam having the same density and prepared from the samefoam-forming composition as the filled foam except that the carbon blackis omitted and the amount of foaming agent is adjusted to equalize thedensities of the filled and unfilled foams.
 2. The foam of claim 1wherein the carbon black is present in the amount of from about 2 toabout 10 percent by weight, based on the weight of the polymer in thefoam.
 3. The foam of claim 2 wherein the carbon black has a meanparticle diameter of from about 20 to about 100 nanometers.
 4. The foamof claim 3 wherein the polymer is selected from the group consisting ofa polyurethane and a polyisocyanurate.
 5. The foam of claim 4 whereinthe polymer is a polyisocyanurate.
 6. The foam of claim 4 wherein thepolyoxyalkylene compound is a capped alkoxylated nonyl phenol.
 7. Thefoam of claim 6 wherein the polyoxyalkylene compound is a cappedethoxylated nonyl phenol which contains about 1 to 4 moles of ethyleneoxide per mole of nonyl phenol.
 8. The foam of claim 7 wherein thecarbon black is a standard rubber-grade type falling under theclassification of ASTM-550.
 9. The foam of claim 1 wherein the polymeris selected from the group consisting of a polyurethane and apolyisocyanurate, and comprises the reaction product of an aromaticpolyisocyanate and an aromatic polyester polyol.
 10. The foam of claim 9wherein the polyoxyalkylene compound is a capped ethoxylated nonylphenol which contains about 1 to 4 moles of ethylene oxide per mole ofnonyl phenol.
 11. The foam of claim 10 wherein the aromaticpolyisocyanate is selected from the group consisting of phenylenediisocyanates, tolylene diisocyanates, diphenylmethane diisocyanates,polyphenyl polymethylene polyisocyanates, isocyanate terminatedprepolymers made from said isocyanates, and mixtures thereof, and thearomatic polyester polyol is the reaction product of a polycarboxylicacid component and an aliphatic diol of the formula:HO--R--OH wherein Ris a divalent radical selected from the group consisting of: (a)alkylene radicals each containing from 2 through 6 carbon atoms, and (b)radicals of the formula:

    --(R.sup.1 O).sub.m --R.sup.1 --

wherein R¹ is an alkylene radical containing from 2 through 6 carbonatoms, and m is an integer of from 1 through 4, and (c) mixturesthereof.
 12. The foam of claim 11 wherein the polymer is apolyisocyanurate.
 13. The foam of claim 11 wherein the carbon black hasa mean particle diameter of from about 20 to about 100 nanometers, andis present in the amount of from about 4 to about 10 percent by weight,based on the weight of the polymer in the foam, and the ethoxylatednonyl phenol is present in the amount of from about 2 to 35 weightpercent, based on the weight of the carbon black.
 14. The foam of claim13 wherein the ethoxylated nonyl phenol contains about 1.5 to 2 moles ofethylene oxide per mole of nonyl phenol and is capped by aceticanhydride.
 15. The foam of claim 14 wherein the polycarboxylic acidcomponent of the aromatic polyester polyol is selected from the groupconsisting of (a) ester-containing by-products from the manufacture ofdimethyl terephthalate, (b) scrap polyalkylene terephthalates, (c)phthalic anhydride, (d) phthalic acid, (e) residues from the manufactureof phthalic acid or phthalic anhydride, (f) terephthalic acid, (g)residues from the manufacture of terephthalic acid, (h) isophthalicacid, (i) trimellitic anhydride, and (j) combinations thereof.
 16. Thefoam of claim 15 wherein the polymer is a polyisocyanurate.
 17. The foamof claim 16 wherein the carbon black is a standard rubber-grade typefalling under the classification of ASTM-550.
 18. The foam of claim 1wherein the polymer is selected from the group consisting of apolyurethane and a polyisocyanurate and the carbon black is present inthe amount of from about 4 to about 10 percent by weight , based on theweight of the polymer is the foam.
 19. The foam of claim 18 wherein thepolyoxyalkylene compound is a capped ethoxylated nonyl phenol whichcontains about 1.5 to 2 moles of ethylene oxide per mole of nonylphenol.
 20. The foam of claim 18 wherein the polyoxyalkylene compound isa capped alkoxylated nonyl phenol.
 21. The foam of claim 20 wherein thepolymer is a polyisocyanurate and comprises the reaction product of anaromatic polyisocyanate and an aromatic polyester polyol.
 22. The foamof claim 21 wherein the polyoxyalkylene compound is a capped ethoxylatednonyl phenol which contains about 1 to 4 moles of ethylene oxide permole of nonyl phenol.
 23. The foam of claim 22 wherein the ethoxylatednonyl phenol contains about 1.5 to 2 moles of ethylene oxide per mole ofnonyl phenol.
 24. The foam of claim 23 wherein the aromaticpolyisocyanate is selected from the group consisting of phenylenediisocyanates, tolylene polymethylene polyisocyanates, isocyanateterminated prepolymers made from said isocyanates, and mixtures thereof,and the aromatic polyester polyol is the reaction product of apolycarboxylic acid component and an aliphatic diol of the formula:

    HO--R--OH

wherein R is a divalent radical selected from the group consisting of:(a) alkylene radicals each containing from 2 through 6 carbon atoms, (b)radicals of the formula:

    --(R.sup.1 O).sub.m --R.sup.1 --

wherein R¹ is an alkylene radical containing from 2 through 6 carbonatoms, and m is an integer of from 1 through 4, and (c) mixturesthereof.
 25. The foam of claim 24 wherein the carbon black is a standardrubber-grade type falling under the classification of ASTM-550.